import turtle as t
t.setup(700,700)
t.speed(0)
t.dot(100,"tan1")
t.left(90)
flag = 1
while flag != 0 :
    num = t.numinput("夹层选择","1.生菜 2.沙拉酱 3.番茄 4.牛肉 5.退出")
    if num == 1:
        color = "forest green"
    elif num == 2:
        color = "light yellow"
    elif num == 3:
        color = "tomato"
    elif num == 4:
        color = "saddle brown"
    else:
        flag = 0
        color = "tan1"
    t.penup()
    t.forward(15)
    t.pendown()
    t.dot(100, color)
t.hideturtle()
t.done()